Term | Definition |
cardiovascular system | also called the circulatory system, consists of the heart, blood vessels, and blood |
heart | a hollow, muscular organ that pumps blood throughout the body |
atrium | referring to one of the two upper chambers that receives blood into the heart |
pacemaker | sends out signals that make the heart muscle contract |
ventricle | referring to one of the two lower chambers the pumps blood out of the heart |
valve | a flap of tissue that prevents blood from flowing backward |
arteries | blood vessels that carry blood away from the heart |
capillaries | tiny, narrow blood vessels where substances are exchanged between the blood and body cells |
veins | blood vessels that carry blood back to the heart |
aorta | the largest artery in the body |
coronary arteries | the term used to describe blood vessels that carry blood to the heart itself in order to supply the cardiac muscle with oxygen-rich blood |
pulse | caused by the alternating expansion and contraction of the artery walls |
diffusion | the process by which molecules move from an area of higher concentration to an area of lower concentration |
blood pressure | a force exerted on the walls of blood vessels that is caused by the force with which the ventricles contract |
blood | made up of plasma, red blood cells, white blood cells, and platelets |
plasma | the liquid part of the blood |
red blood cells | take up oxygen in the lungs and deliver it to cells elsewhere in the body |
hemoglobin | an iron-containing protein that binds with oxygen |
white blood cells | the body's disease fighters |
platelets | cell fragments that play an important part in forming blood clots |
lymphatic system | a network of veinlike vessels that returns the fluid to the bloodstream |
lymph nodes | filter lymph, trapping bacteria and other disease-causing microorganisms in the lymph fluid |
atherosclerosis | a condition in which an artery wall thickens as a result of the buildup of fatty materials |
heart attack | occurs when blood flow to part of the heart muscle is blocked |
hypertension | a condition in which a person's blood pressure is consistently higher than normal |